Pounds to kilograms, ounces to grams, stone to pounds - plus troy units for precious metals - all from the exact legal definition of the pound, not an approximation.
| From | Equals |
|---|---|
| 1 pound | 0.45359237 kg |
| 1 kilogram | 2.204622622 lb |
| 1 ounce | 28.34952313 g |
| 1 gram | 0.03527396195 oz |
| 1 stone | 6.35029318 kg |
| 1 ton (us short) | 907.18474 kg |
| 1 tonne (metric) | 2204.622622 lb |
| 1 ounce (troy) | 31.1034768 g |
Every value in this table is computed by the same conversion engine as the tool above - not typed in by hand - so the tool and the table can never disagree.
The same 1959 international agreement that fixed the inch also defined the avoirdupois pound as exactly 0.45359237 kilograms. Every ounce (1/16 lb), stone (14 lb), US short ton (2,000 lb), and UK long ton (2,240 lb) follows exactly from it. The grain - the oldest unit in the system - is defined as 1/7000 of a pound, and it's the one unit shared between the everyday (avoirdupois) system and the troy system used for precious metals.
A troy ounce (used for gold and silver prices) is 480 grains ≈ 31.103 g, while the everyday avoirdupois ounce is 437.5 grains ≈ 28.350 g - so a troy ounce is about 10% heavier, even though a troy pound (12 troy oz) is lighter than a regular pound (16 oz). This converter includes both systems, plus the slug - the engineering mass unit defined so that 1 pound-force accelerates it at 1 ft/s². Strictly speaking, all of these are units of mass; "weight" in everyday speech means the same thing, which is how this page uses it.